Electrolyte solution containing iodide additives and sulfur dioxide-based secondary battery including the same

Abstract

The present invention relates to an electrolyte solution containing an iodide additive, and a sulfur dioxide-based secondary battery including the same. An electrolyte solution for a sulfur dioxide-based secondary battery according to the present invention includes sulfur dioxide (SO 2 ), an alkali metal salt, and an iodide additive. An iodide additive is added to an electrolyte solution, and thus energy efficiency, a long-life characteristic, and stability of a negative electrode of a sulfur dioxide-based secondary battery can be improved.

What is claimed is: 
     
         1 . An electrolyte solution for a sulfur dioxide-based secondary battery, the electrolyte solution comprising sulfur dioxide (SO 2 ), an alkali metal salt, and an iodide additive. 
     
     
         2 . The electrolyte solution for a sulfur dioxide-based secondary battery according to  claim 1 , wherein the iodide additive is NaI or LiI. 
     
     
         3 . The electrolyte solution for a sulfur dioxide-based secondary battery according to  claim 1 , wherein a content of the iodide additive is 0.001 to 0.5 M. 
     
     
         4 . The electrolyte solution for a sulfur dioxide-based secondary battery according to  claim 1 , wherein a content of the iodide additive is 0.03 to 0.1 M. 
     
     
         5 . The electrolyte solution for a sulfur dioxide-based secondary battery according to  claim 1 , wherein the sulfur dioxide and the alkali metal salt are included as NaAlCl 4 -xSO 2  (1.5≦x≦3.0) or LiAlCl 4 -xSO 2  (1.5≦x≦3.0). 
     
     
         6 . A sulfur dioxide-based secondary battery comprising an electrolyte solution containing sulfur dioxide (SO 2 ), an alkali metal salt, and an iodide additive. 
     
     
         7 . A sulfur dioxide-based secondary battery, comprising:
 a negative electrode containing sodium or lithium;   a positive electrode containing a carbon material; and   an electrolyte solution containing sulfur dioxide (SO 2 ), an alkali metal salt, and an iodide additive.   
     
     
         8 . The sulfur dioxide-based secondary battery according to  claim 7 , wherein the iodide additive is NaI or LiI. 
     
     
         9 . The sulfur dioxide-based secondary battery according to  claim 7 , wherein a content of the iodide additive is 0.001 to 0.5 M. 
     
     
         10 . The sulfur dioxide-based secondary battery according to  claim 7 , wherein a content of the iodide additive is 0.03 to 0.1 M. 
     
     
         11 . The sulfur dioxide-based secondary battery according to  claim 7 , wherein the sulfur dioxide and the alkali metal salt are included as NaAlCl 4 -xSO 2  (1.5≦x≦3.0) or LiAlCl 4 -xSO 2  (1.5≦x≦3.0). 
     
     
         12 . The sulfur dioxide-based secondary battery according to  claim 7 , wherein the negative electrode is a sodium metal or a lithium metal.